Quantization matrix encoding/decoding method and device, and recording medium storing bitstream

Abstract

Disclosed herein is a video decoding method including determining one or more adaptation parameter sets including a quantization matrix set including a plurality of quantization matrices, determining an adaptation parameter set including a quantization matrix set applied to a current picture or a current slice from among the one or more adaptation parameter sets, dequantizing transform coefficients of a current block of a current picture or a current slice based on the quantization matrix set of the determined adaptation parameter set, and reconstructing the current block based on the dequantized transform coefficients, wherein the adaptation parameter set includes coding information applied to one or more pictures or slices.

The invention claimed is: 
     
         1 . A video decoding method comprising:
 determining, based on type information of an adaptation parameter set, a type of the adaptation parameter set; and   in response to the type information indicating a quantization type, decoding information on a current quantization matrix in the adaptation parameter set,   wherein the current quantization matrix is reconstructed by one of a quantization matrix copy mode, an inter-quantization-matrix prediction mode or an intra-quantization-matrix DPCM (Differential Pulse Code Modulation) mode,   wherein whether the quantization matrix copy mode is applied to reconstruct the current quantization matrix is determined based on a quantization matrix copy mode flag decoded from a bitstream,   wherein whether the inter-quantization-matrix prediction mode is applied to reconstruct the current quantization matrix is determined based on an inter-quantization-matrix prediction mode flag decoded from the bitstream, and   wherein the inter-quantization-matrix prediction mode flag is decoded from the bitstream in response to the quantization matrix copy mode flag indicates that the quantization matrix copy mode is not applied to reconstruct the current quantization matrix.   
     
     
         2 . The method of  claim 1 , wherein in response to the inter-quantization-matrix prediction mode flag indicating that the inter-quantization-matrix prediction mode is not applied to the current quantization matrix, the current quantization matrix is reconstructed by the intra-quantization matrix DPCM mode. 
     
     
         3 . The method of  claim 1 , wherein in response to the quantization matrix copy mode being applied, a coefficient of the current quantization matrix is copied from a reference quantization matrix. 
     
     
         4 . The method of  claim 3 , wherein a size of the reference quantization matrix is specified by identification information specifying one of quantization matrices reconstructed prior to the current quantization matrix. 
     
     
         5 . The method of  claim 4 , wherein the identification information represents a difference between an identifier of the current quantization matrix and an identifier of the reference quantization matrix. 
     
     
         6 . The video decoding method of  claim 1 , wherein in response to the inter-quantization-matrix prediction mode being applied to reconstruct the current quantization matrix, a reference quantization matrix is determined,
 wherein a coefficient of the current quantization matrix is obtained by summing a matrix coefficient of the reference quantization matrix and a differential quantization matrix coefficient representing a difference between the coefficient of the current quantization matrix and the coefficient of the reference quantization matrix.   
     
     
         7 . The method of  claim 1 , wherein the method further comprises:
 decoding, from a bitstream, quantization matrix enabled information, the quantization matrix enabled information indicating whether a quantization matrix set included in the adaptation parameter set is applied to a block, to which an inverse secondary transform is applied, the quantization matrix set including a plurality of quantization matrices, and   wherein in response to the quantization matrix enabled information indicating that the quantization matrix set in the adaptation parameter set is not applied, the quantization matrix of the block to which the inverse secondary transform is applied is determined as a default quantization matrix.   
     
     
         8 . The method of  claim 6 , wherein in response to the quantization matrix enabled information indicating that the quantization matrix set in the adaptation parameter set is applied, the quantization matrix of the block to which the inverse secondary transform is applied is determined as one of the quantization matrices in the adaptation parameter set. 
     
     
         9 . A video encoding method comprising:
 encoding type information of an adaptation parameter set representing a type of the adaptation parameter set; and   encoding information on a current quantization matrix in the adaptation parameter set in response to the type of the adaptation parameter set being a quantization type,   wherein the current quantization matrix is encoded by one of a quantization matrix copy mode, an inter-quantization-matrix prediction mode or an intra-quantization-matrix DPCM (Differential Pulse Code Modulation) mode,   wherein a quantization matrix copy mode flag indicating whether the quantization matrix copy mode is applied to encode the current quantization matrix or not is encoded into a bitstream,   wherein an inter-quantization-matrix prediction mode flag indicating whether the inter-quantization-matrix prediction mode is applied to encode the current quantization matrix is encoded into the bitstream, and   wherein the inter-quantization-matrix prediction mode flag is encoded to the bitstream in response to the quantization matrix copy mode flag is encoded to indicate that the quantization matrix copy mode is not applied to encode the current quantization matrix.   
     
     
         10 . A device for transmitting compressed video data, comprising:
 a processor configured to obtain the compressed video data; and   a transmitter configured to transmit the compressed video data,   wherein obtaining the compressed video data comprises:   encoding type information of an adaptation parameter set representing a type of the adaptation parameter set; and   encoding information on a current quantization matrix in the adaptation parameter set in response to the type of the adaptation parameter set being a quantization type,   wherein the current quantization matrix is encoded by one of a quantization matrix copy mode, an inter-quantization-matrix prediction mode or an intra-quantization-matrix DPCM (Differential Pulse Code Modulation) mode,   wherein a quantization matrix copy mode flag indicating whether the quantization matrix copy mode is applied to encode the current quantization matrix or not is encoded into a bitstream,   wherein an inter-quantization-matrix prediction mode flag indicating whether the inter-quantization-matrix prediction mode is applied to encode the current quantization matrix is encoded into the bitstream, and   wherein the inter-quantization-matrix prediction mode flag is encoded to the bitstream in response to the quantization matrix copy mode flag is encoded to indicate that the quantization matrix copy mode is not applied to encode the current quantization matrix.